hippo | Ecology for the Masses

Invasive Snails and Their Hippo Victims

Posted on September 21, 2022 by Adam Hasik Leave a comment

Image credit: Muhammad Mahdi Karim, CC BY-SA 4.0, Image Cropped

Invasive snails, parasite spillback, and potential parasite spillover drive parasitic diseases of Hippopotamus amphibius in artificial lakes of Zimbabwe (2021) Schols et al., BMC Biology, https://doi.org/10.1186/s12915-021-01093-2

The Crux

Artificial lakes can be a huge plus for the regions where they are constructed. People come to hang out at them, they can serve as habitat for local or migrating species, and they can also improve water accessibility. In fact, the majority of the research that I did for my PhD took place in artificial, human-made lakes (see here and here). Yet, these artificial lakes can also wreak havoc by destroying local ecosystems and introducing invasive species. Furthermore, because humans build communities around these lakes there is a risk of increased transmission of parasites to livestock and humans alike.

One group of common invasive species in these artificial lakes are snails, which serve as intermediate hosts for many parasites (see Did You Know?). Introduced water plants (like hyacinth) often harbor invasive species like the snails, and dams built to make artificial lakes often block snail predators from accessing the lakes, which means that the snails increase in number due to the release from predation pressure. Today’s authors wanted to understand how invasive snails modified parasite transmission within an artificial lake.

Paper of the Week

Using eDNA to Avoid Being Eaten on the Job

Posted on May 6, 2020 by Sam Perrin One comment

Image Credit: pxfuel, CC0 1.0, Image Cropped

Monitoring the silver carp invasion in Africa: a case study using environmental DNA (eDNA) in dangerous watersheds (2020) Crookes et al., NeoBiota, http://doi.org/10.3897/neobiota.56.47475

The Crux

One thing the last two months have taught us all is that testing for a problem is crucial. The earlier you catch a problem, the more of a chance you have to stop that problem spreading. Coronavirus is one example, invasive species is another. Detecting an invader arriving early on means you can potentially remove it before it has become properly established, saving millions of dollars down the line.

But often testing isn’t practical. Take freshwater environments. Sometimes a river may be hard to get to. Sometimes it may be infested with crocodiles and hippos. Makes regular testing methods like electrofishing or gillnetting a bit tricky.